The Curse of Phrenology

The idea that you can look at someone’s physique and gain insight into their temperament is widely viewed as quackery. However, there is no real basis for this stance because anyone with an ounce of google can dig up published peer reviewed scientific evidence that a correlation actually does exist between certain personality traits and a person’s somatotype or body type. Scientists are not obligated to research or correct every idea that comes along. They pick things that catch their interest. If an area of research isn’t “hot” or even worse if it’s held in some kind of disdain there is little incentive to pursue it. Giving somatotype based personality research the pseudo-science label is a sure way to diminish a doctoral candidate’s interest in the subject. This is especially the case when introductory psychology text books are their main source of critical exposure.

In the middle of the twentieth century (1930-1960) William Sheldon developed his system of describing physiques using a 7 point scale for each of three dimensions; endomorphy (stout), mesomorphy (muscular), and ectomorphy (linear/thin). Sheldon found fairly high correlations between body-type and temperament but he was criticized for doing both the somatotyping and the interviews that formed the basis of his assessments. This left him open to claims that his research was biased due to the halo effect. After Sheldon’s original study a small number of researchers did similar research, but they used self-report tests to keep the somatotyping process separate from the temperament assessments. These more orthodox research methods produced correlations that were much lower but significantly in the same direction as Sheldon’s. In spite of these positive results the myth that somatotype is a “pseudo-science just like Phrenology” persists. That’s the Curse of Phrenology.

There is a good reason for phrenology’s bad reputation. In spite of the public’s enthusiasm for the idea of predicting personality based on skull topography, scientists found no correlation between head bumps and personality. Finally, when autopsies were performed there was no evidence that the soft tissue of the brain had the ability to push out the hard bone of the skull to produce a bump. That pretty much ended the possibility for any re-emergence of phrenology. But, what’s really going on when people accuse Sheldon’s theory of being “just like phrenology”. They are really expressing their belief that any effort to predict personality by means of some physical measurement is bound to fail. Equating somatotype with phrenology is a fallacious argument based on a poor analogy. Just because two things are similar in some respects doesn’t mean that they are necessarily similar in other ways. One big way in which somatotype and phrenology differ is that phrenology can’t predict personality traits whereas somatotype actually does. That is a significant difference that should be an antidote to the claims made against Sheldon’s theory. Any other similarities between somatotyping and phrenology are meaningless.

There is a deeper link between somatotype and phrenology in which they are significantly similar and that is at the core of the “Curse of Phrenology”. They both are associated with the “nature” side of the nature/nurture question. In the early twentieth century there was the beginning of a revolt against hereditarian theories of human behavior. Americans were tired of the arrogant claims of genetic superiority by the aristocratic class. The idea that your genes could influence your status tempts its adherents with the eugenic seduction. The results of the eugenic seduction can end up like the Nazis justifying their atrocities using theories of genetic superiority. After World War II any suggestion of inherited abilities were summarily rejected in the court of ideas. It was bad enough that there was this association of racism with constitutional psychology, but for whatever reason Sheldon explicitly spoke out in favor of eugenics to the point that he developed an enthusiastic interest in the American Nazi Party. No one wanted to run their careers off that ideological cliff. There were plenty of less controversial areas that psychologists could occupy themselves without taking on unnecessary baggage. The psychology of success, occupational interests, personality identification and growth through therapy and training all focused on human potential and avoided the idea of human limitation.